Vessel Wall Connective Tissue Studies: These will consist of structural studies in which we are attempting to elucidate the structure of the protein core of aorta tissue proteoglycan and of aorta structural glycoprotein. We will also investigate the ability of aortic smooth muscle cells to synthesize connective tissue components under a variety of pre-atherosclerotic conditions will be studied. Luminal Thrombus Formation: The effect of infusion of a variety of different molecular weight dextrans and other substances will be studied insofar as they effect the deposition of thrombi following surgery.